So I added override => 1 and now everything is working.

Ah, that makes sense. If you had previously submitted the form with that specific checkbox being unchecked, then the normal behavior of CGI.pm is to keep that existing state when it prints the new copy of the HTML -- that would explain why the results with no input using my code didn't match what you were seeing.

To make sure that your form is always in the "pristine" state rather than inheriting from the input parameters it received, then you have to tell CGI.pm to do it that way.

The CGI.pm documentation for 4.51 explains this in the CGI::HTML::Functions "CREATING FILL-OUT FORMS:" section (as does 4.60 in the equivalent section of the docs):

Another note The default values that you specify for the forms are only used the first time the script is invoked (when there is no query string). On subsequent invocations of the script (when there is a query string), the former values are used even if they are blank.

It then goes on to explain that you can either use the param() method to set the value for that parameter to what you want, or you can use the override flag to have the "default" values you supply in your code used even if there was an input value from the query string or post parameters.

In reply to Re^2: is there anything more VEXING than checking the $cgi->checkbox ? by pryrt
in thread is there anything more VEXING than checking the $cgi->checkbox ? by misterperl

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.